Process of recovering resorcinol



Patented June 10, 1930 ra s PATENT OFFICE IVAN GUIBELMANN AND CLYDE O. HENKE, OF SOUTH MILWAUKEE, WISCONSIN, AS- SIGNORS TO THE NEWPORT COMPANY, 01 CARBOLLVILLE, WISCONSIN, A CORIORA- TION OF DELAWARE No Drawing.

This invention relates to a process for the recovery of resorcinol when resorcinol is used or the purification and decolorizing of resins. In our vco-pending application entitled: Process of purifying and decolorizing rosins With resorcinol, Serial No. 208,407, filed July 25, 1927, of which the present application is a continuation in part, 'We have described a method of obtaining high-grade rosins by the purification of low-grade rosins by means of resorcinol. Inasmuch as the resorcinol used as a solvent for the impurities normally contained in rosin is more costly than the rosin itself, it is extremely important from a commercial standpoint that practically all of the resorcinol be recovered for reuse.

It is therefore an object of this invention treated With resorcinol at an elevated temperresorcinol dissolved in the resin solution.

According to .our process, this is accom- PROCESS 0J5 RECOVERING RESORCINOL Application filed December 24,1927. Serial No. 242,514.

plishcd by extraction with water, whereby 'tlx' resorcinol, on account of its high solubility in a or hot, but preferably hot, the resorcinol is dissolved away from the magma, leaving the 1mpur1t1es and coloring matter practically undissolved. The resulting more concentrat- 'ed resorcinol solution is then evaporated and the resorcinol is obtained as the residue} Evaporation may be continued until the resorcinol content reaches about 90%. If desired, the resorcinol may be further purified by distillation in vaeuo.

For re-use in subsequent purifying operations, the resorcinol obtained by simple evap-' oration has been found of satisfactory quality, as the presence of small quantities of impurities is not detrimental. During the evaporation some of the resorcinol distills over With the Water, but thisresorcinol can also be conserved by re-use of the distillate for extracting other portions of resorcinol from the rosin solution.

By following thisgen era-l method, it has been found possible to obtain over 99% recovery O'Ethc resorcinol.

It was surprising to find that practically all ofthe resorcinol contained in the rosin solution and in the resorcinol mass could he recovered by simple extraction with Water and that the recovered resorcinol as obtained by evaporation of the water extracts would be of sufficiently high purity for reuse.

not be' cooled to a point at which the resor- Without limiting our invention to any particular procedure, the following example, in which parts by weight are given, will serve to illustrate our'method in its preferred form.

Emampla- To 1920 parts of a petroleum naphtha solution containing about 200 parts of rosin, at 90 to 95 (3., are added while agitating, 40 parts of resorcinol. The resorcinol added may contain some water, say 10%. The mixture is maintained at this temperature under agitation for about 20 minutes and is-then cooledtoprdinary temperatures, say 20 to C. The rosinsolution is then separated from the dark mass consisting princially of resorcinol and color bodies.

It will be understood that the mixture need cinol mass becomes solid, but that a part of the resorcinol mass may be separated as a liquid while the mixture is still hot.

The rosin solution, after separation from the resorcinol mass, is successively agitated four to six times with a total of 600 parts of cinol.

water, and after each agitation allowed to stand until separation into layers has been effected. "Each time the aqueous layer is separated by gravity from the rosin solution, until finally-it is practically free of resor- The successive wash waters containing the resorcinol from the rosin solution are used to treat the separated resorcinol mass I containing the impurities.

The mainportion of the resorcinol mass is preferably boiled up with the successive wash-waters as obtained above, whereby the resorcinol" dissolves in the wash gvaters and is separated'practically completely fromthe major portion of the pitch and other rosin impurities. The successive washes, after being combined, give a 6 to 7 solution of resorcinol. This resorcinol solution contains some pitch in suspension and in solution. The suspended pitch may be filtered off. The filtrate is then evaporated to a concentration wherein the residue analyzes 85 to 90% re sorcinol.

The quantities of water used and the number of washings employed may obviously be variedas required by good operation. 7

The recovery of the resorcinol by the above method, provided the distillate from the evaporation step is used in subsequent extraction steps, amounts to about 99% of theoryor higher. Furthermore, the resorcinol obtained by this method of recovery is entirely suited for re-use in the process for the extraction of coloring matter and impurities from the rosin.

a As an alternative procedure to theevaporat1on step for the recovery of resorcinol from its water solution, the resorcinol may-he. ex-

tracted from its water solution by any other parting from the principles of this invention and we, therefore, do not purpose limiting the patent granted hereon, otherwise than necessitated by the prior art.

' We claim as our invention:

1. The process of recovering resorcinol from a resorcinol mass containing impurities extractedfrom rosin, which comprises dissolving the resorcinol out of the mass with water andrecovering the resorcinol from the water solution of the resorcinol.

' 2. The process of recovering. resorcinol from a resorcinol mass containing impurities extracted from rosin, which comprises boiling the mass with water to dissolve the resorcinol, separating the water solution of resorcinol from the undissolved impurities and evaporating off the water to recover the resorcinol content. I

X 3. The process of recovering resorcinol made and numerous deitails of the process may from a mixture containing a purified rosin purities, extractingany resorcinol dissolved in the rosin solutionwith water, using the re sulting dilute resorcinol solution to disolve the resorcinol away from the impurities inthe resorcinol mass and'recovering the resorimpurities, extracting any resorcinol dis solved in the rosin solution with water, using the resulting dilute resorcinol solution to-dissolve the resorcinol away from the impurities in the resorcinol mass, filtering the resorcinol solution so obtained to remove suspended impurities and evaporating the water' from the filtered solution to recover resorcinol. 5 .5. The process of recovering resorcinol from a mixture containing a purified rosin solution and an impure resorcinol mass, which comprises separating the rosin solutionfrom the resorcinol mass containing the impurities, extracting any resorcinol dissolved in the rosin solution with water, uslng the resulting dilute resorcinol solution to discinol from its resulting water solution by dissolve the resorcinol away from the impurities v in the'resorcinol mass, filtering the resorcinol solution so obtained to remove suspended 1mpurities, evaporating the water from thefil tered solutionto recover resorcinol, and using the distillate obtained by evaporation of the resorcinol solution in the extraction of resorcinol froin a succeeding rosin solution.

- 6. The process of recovering resorcinol from a resorcinol mass containing impurities extracted from rosin, which comprises boiling the mass with water to dissolve the resorcmol, separating the water solution of 

